Pipe management system for negative angle drilling

ABSTRACT

A pipe handling system for a platform based drill includes a drilling platform with a frame structure having a first end, a second end opposite the first end, and first and second opposite sides. A mast is supported on a pivotal connection to the platform permitting the mast to be pivotally adjusted to a negative drilling angle whereby an upper portion of the mast leans in a first direction extending toward the first end of the frame structure and away from the second end of the frame structure. The mast includes a length direction and has an open cross-section with a concave side facing in the first direction and a convex side facing in a second direction opposite to the first direction. A pipe handling unit mounted to the concave side of the mast is configured to support a drill pipe within the mast when the mast is pivotally adjusted to the negative drilling angle.

TECHNICAL FIELD

The present disclosure is directed to a pipe management system and, more particularly, is directed to a pipe management system for negative angle drilling.

BACKGROUND

Excavating is employed to create mines, quarries, etc., in order to obtain desirable material such as ore or stone. In addition to using various types of heavy excavating equipment, drill-and-blast operations are commonly used to fragment material so it can be loaded and hauled. For example, overburden may need to be removed in order to reach the desirable material. Drill-and-blast operations may include drilling different types of blast holes, and some blast holes, for example pre-split holes, may require negative angle drilling. For example, pre-split holes are drilled in a “bench” of an excavation typically at an angle, referred to as a “negative angle,” that aligns with the slope of a “highwall” of the excavation, for example 5 to 15 degrees from a vertical direction.

Current drill-and-blast operations employ platform based drills to bore production holes, but not for boring pre-split holes which must be formed close to the highwall and substantially at the negative angle of the highwall in order to maintain the desired slope of the highwall as the depth of the bench is increased and the height of the highwall is increased. Since current platform based drills are not capable of drilling at the required negative angle of the highwall, the usual drill-and-blast operation will employ various dedicated pre-split drills that are usually boom mounted drills. Accordingly, a drill-and-blast operation in an open pit mine ordinarily may require a diverse fleet of drilling machines in order to form the different types of required holes.

During a drilling operation with a platform based drill, sections of drill pipe may be added to a drill column in order to increase the depth of drilling, and later removed as the drill column is disassembled. Various systems for managing drill pipe have been developed to manipulate and stabilize the drill pipe both during drilling and when adding or removing sections of drill pipe. Such drill pipe management systems typically include pipe handling equipment that requires substantial space, either externally of the mast or within the mast. Platform based drills capable of drilling blast holes at negative angles may enable drilling of all the various types of blast holes, including production and pre-split holes. Drilling negative angle holes with an open side of the mast inclined downwardly presents pipe management issues, particularly since gravity tends to work against pipe alignment as the mast tilts to negative angles. Current pipe management systems have not proven adequate for negative angle drilling.

There exists a need for a relatively simple and cost-effective pipe management system that occupies minimum space and effectively handles drill pipe as it is installed and removed from the drill column. It would be both beneficial and desirable to provide the mast of a drilling machine capable of negative angle drilling with a system that will both occupy minimum space and support negative angle drilling and that can hold and maintain drill pipe stable during both positive and negative angle drilling as well as vertical drilling. It would be both beneficial and desirable to provide a platform based drill that is capable of boring both vertical and positive angle production holes, is capable of boring negative angle pre-split holes, and includes support structure sufficient to accommodate pipe handling and management with a mast tilted at a negative angle.

One type of drilling machine used for drill and blast operations is disclosed in U.S. Pat. No. 5,931,238 issued to Gilmore et al. on Aug. 3, 1999 (“the '238 patent”). The '238 patent discloses a blast hole drill with a drill head mounted on a mast and a pipe carousel on the drill deck. A drill pipe handling system includes an arm assembly that transfers a drill pipe from a position on a pipe carousel to a position adjacent the mast. The arm assembly includes a single jaw pipe grasping assembly and a double jaw grasping assembly to hold a drill pipe as it is transferred by the arm assembly.

While the drilling machine of the '238 patent may be useful for some drilling purposes, the '238 patent does not disclose a pipe management system that supports negative angle drilling. In addition, the drill pipe handling system disclosed in the '238 patent may be unduly complicated and adapted only to drilling machines where drill pipes are stored in horizontal position on the deck. Furthermore, the drill pipe handling system disclosed in the '238 patent requires a substantial amount of space in order to manipulate between a pipe loading and pipe storage position. Accordingly, the system of the '238 patent may not be suitable for drilling operations where the pipe carousel is positioned parallel to the mast.

The disclosed pipe management system for negative angle drilling of the present disclosure solves one or more of the problems set forth above and/or other problems of the prior art.

SUMMARY

In one aspect, the present disclosure is directed to a pipe handling system for a platform based drill comprising a drilling platform including a frame structure having a first end, a second end opposite the first end, and first and second opposite sides. The pipe handling system for a platform based drill may include a mast supported on a pivotal connection to the drilling platform permitting the mast to be pivotally adjusted to a negative drilling angle whereby an upper portion of the mast leans in a first direction extending toward the first end of the frame structure and away from the second end of the frame structure, the mast including a length direction and having an open cross-section with a concave side facing in the first direction, and a convex side facing in a second direction opposite to the first direction. The pipe handling system also may include a pipe handling unit mounted to the concave side of the mast and configured to support a drill pipe within the mast when the mast is pivotally adjusted to the negative drilling angle.

In another aspect, the present disclosure is directed to a pipe handling unit on a mast of a drilling platform and may include a mast having a length direction and a generally C-shaped cross section including a back element and first and second side elements partially enclosing a space within the mast, and including an open front. The pipe handling unit may be within the space and may include a first support linkage having first and second ends and pivotally attached at the first end to the first side element, and a second support linkage having first and second ends and pivotally attached at the first end to the second side element.

In yet another aspect, the present disclosure is directed to a method of managing drill pipe to support negative angle drilling with a drilling machine including a mast having a length direction and a generally C-shaped cross section with a back element and first and second side elements partially enclosing a space, and including an open front. The method may include pivoting the mast to a negative angle with the mast leaning from a vertical direction toward the direction of the open front and away from the back element. The method also may include moving in the length direction of the mast a pair of opposed arcuate support elements that are partially cylindrical about axes extending parallel to the length direction of the mast. The method also may include, while moving the pair of opposed arcuate support elements, maintaining the axes extending parallel to the length direction of the mast to engage and support a section of drill pipe. The method also may include moving the pair of opposed arcuate support elements again in the length direction of the mast. The method also may include, while moving the pair of opposed arcuate support elements again, maintaining the opposed arcuate support elements parallel to the length direction of the mast to release the section of drill pipe.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary platform based drill supported on a bench adjacent a highwall of a mine or quarry;

FIG. 2 is a perspective view of a portion of a mast mounted at an end of a drilling platform of an exemplary drilling machine;

FIG. 3 is a cross section through a mast showing certain details of an exemplary drilling machine with a pipe rack carousel in a loading/unloading position;

FIG. 4 is a cross section through a mast showing certain details of an exemplary drilling machine with a pipe rack carousel in a position withdrawn from the drill column;

FIG. 5 is a perspective view of a pipe handling unit in a mast;

FIG. 6 is another perspective view of a pipe handling unit in a mast;

FIG. 7 is a perspective view of certain details of an exemplary platform based drill including a pipe handling unit engaging a drill pipe section;

FIG. 8 is another perspective view of certain details of an exemplary platform based drill including a pipe handling unit engaging a drill pipe section;

FIG. 9 is another perspective view of certain details of an exemplary platform based drill including a pipe handling unit in disengaged position; and

FIG. 10 is a flow chart for an exemplary method according to the disclosure.

DETAILED DESCRIPTION

FIG. 1 illustrates certain aspects of the disclosure including one environment in which the disclosed machine may be employed and in which the disclosed method may be realized. The environment illustrated in FIG. 1 is an excavation 10, such as an open pit mine, quarry, etc. Such an excavation 10 commonly is formed by a combination of excavating and haulage techniques with various types of excavating machines and haulage vehicles, and drill-and-blast techniques using drilling machines and explosives. At the various levels reached in the course of formation of excavation 10, the surface on which working equipment rests may be designated a bench 12, and an adjacent wall of the excavation 10 rising above the bench 12 may be designated a highwall 14. For purposes of this disclosure, bench 12 may be said to include a bench surface 13, and highwall 14 may be said to include a face 15. Face 15 typically may form an obtuse angle with bench surface 13, and face 15 typically may slope at an acute angle α relative to vertical direction 17

FIG. 1 diagrammatically illustrates a stripped-down version of an embodiment of a platform based drill 16 showing only certain basic components. Platform based drill 16 may include a drilling platform 18 which in turn may include, among other things that are not illustrated in FIG. 1, a frame structure 20. Drilling platform 18 may be supported and leveled, for example during a drilling operation, by a plurality of vertically adjustable supports, such as vertically adjustable support 22. Platform based drill 16 also may include an operator station 28 which may house suitable controls and provide accommodations for personnel. Frame structure 20 may include a first end 32 and a second end 34 that is opposite first end 32. In addition, frame structure 20 may include two opposite sides, the view in FIG. 1 showing first side 33. Platform based drill 16 also may include a mast 30 extending in a length direction A and supporting drilling equipment.

During the course of forming excavation 10, bench 12 may be drilled and blasted in order to aid further removal of overburden and/or desirable ore material, for example. A common practice is to attempt to maintain face 15 of highwall 14 at an angle α relative to vertical direction 17 that is commensurate with maintaining stability of highwall 14. For example, an exemplary angle α of slope for face 15 of highwall 14 may be on the order of 15 degrees from vertical direction 17. Mast 30 may be supported and mounted for pivotal movement adjacent first end 32 and adjacent a lower portion 29 of mast 30, permitting mast 30 to be pivotally adjusted to a negative drilling angle equivalent to angle α whereby an upper portion 31 of mast 30 leans in a first direction extending toward first end 32 of frame structure 20 and away from second end 34 of frame structure 20.

As illustrated in FIG. 1, when mast 30 of platform based drill 16 is pivotally adjusted to the negative drilling angle α, mast 30 will be substantially parallel to face 15 of highwall 14. In this orientation wherein mast 30 is substantially parallel to face 15 of highwall 14, a series of pre-split holes, such as pre-split hole 36, may be drilled at the negative angle of face 15 and closely adjacent highwall 14 in order to facilitate blasting and maintaining of face 15 of highwall 14 at a desirably stable angle as excavation proceeds. The term “negative angle” is employed to designate an angle of a mast 30 relative to a drilling platform 18 of a drilling machine wherein upper end 31 of the mast 30 leans away from, or outbound of, the drilling machine in a direction away from the non-drilling end (i.e., second end 34 in FIG. 1) of the drilling platform 18. Operator station 28 also may be located adjacent first end 32 and proximate mast 30 permitting a drilling operation and pivotal adjustment of mast 30 to be readily visible to an operator.

FIG. 2 is a perspective view of platform based drill 16 adjacent first end 32 of frame structure 20 with certain machine components removed in order to better illustrate certain other components. FIG. 2 illustrates lower portion 29 of mast 30 and with mast 30 inclined from the vertical direction 17 (FIG. 1) at a negative angle similar to that diagrammatically illustrated in FIG. 1. First end 32 may include an opening 48 within frame structure 20. Mast 30 may extend within opening 48 and may be pivotally mounted, for example via a pivotal connection 49, to frame structure 20. Opening 48 may be centrally located between first side 33 and second side 35 of frame structure 20. Mast 30 may include a baseplate 60, and baseplate 60 may include a drill hole 61. Mast 30 may be formed with a cross-section that may be characterized as an open cross-section with a concave side 38 facing in a first direction B extending toward first end 32 of frame structure 20 and away from second end 34 (FIG. 1) of frame structure 20, and an opposing convex side 39 facing in a second direction C opposite to first direction B. Pipe handling unit 70 is visible in FIG. 2 mounted to concave side 38 of mast 30 and will be described in more detail subsequently.

FIGS. 3 and 4 illustrate cross-sections taken through an exemplary embodiment of mast 30 with the view in FIGS. 3 and 4 being toward lower portion 29 (FIGS. 1 and 2) and baseplate 60 of mast 30. The open cross-sectional shape of mast 30 may include back element 42 and first and second side elements 44 and 46 which may diverge at a suitable angle from back element 42 as illustrated. Accordingly, the cross-section of mast 30 may include an open front 67 that may have a greater width than back element 42. However, it is within the scope of this disclosure and it is contemplated that the open cross-section of mast 30 also may include a cross-section in which first and second side elements 44 and 46 do not diverge from back element 42, but instead are perpendicular to back element 42 with the open front being of the same width as back element 42. In addition, it is within the scope of this disclosure and it is contemplated that the open cross-section of mast 30 could be curved such that back element 42 and first and second side elements 44 and 46 form parts of the curve. In either alternative form, back element 42 and first and second side elements 44 and 46 may form elements of concave side 38 and convex side 39, described previously, of mast 30. The open cross-sectional shape of mast 30 also may be characterized as generally C-shaped inasmuch as, whether formed with diverging first and second side elements 44, 46, with first and second side elements 44, 46 perpendicular to back element 42, or entirely curved, the cross-sectional shape is similar to and resembles the letter “C.”

A pipe rack carousel 62 may be suitably mounted adjacent mast 30 and may include holders 63 for a plurality of drill pipe sections, such as drill pipe section 66 illustrated at drill column 65. Pipe rack carousel 62 may be mounted to swing about a pivot rod 64, for example mounted to baseplate 60 of mast 30, to move a drill pipe section 66 to or from drill column 65. Pipe rack carousel 62 is illustrated in FIG. 3 as pivoted to a position for transferring a drill pipe section 66 to or from drill column 65, while pipe rack carousel 62 is illustrated in FIG. 4 as pivoted to a rest position withdrawn from drill column 65. Pipe handling unit 70 is illustrated in FIG. 3 engaging and holding a drill pipe section 66 at drill column 65, while pipe handling unit 70 is illustrated in FIG. 4 in a rest position withdrawn from contact with drill pipe section 66.

FIGS. 5 and 6 are perspective views, each taken at a slightly different angle from the other, of pipe handling unit 70 mounted to concave side 38 of mast 30 and configured to support a drill pipe section 66 (FIG. 3, for example) within mast 30 when mast 30 is adjusted to any of a vertical position, a positive drilling angle, or a negative drilling angle. As described in connection with FIGS. 3 and 4, concave side 38 of mast 30 may include back element 42 and first and second side elements 44 and 46. Pipe handling unit 70 may include a first support linkage 52, and a second support linkage 56. First support linkage 52 may be pivotally attached at its first end 53 to first side element 44, and pivotally connected at its second end 54 to first arcuate support element 72. Second support linkage 56 may be pivotally attached at its first end 57 to second side element 46, and pivotally connected at its second end 55 to second arcuate support element 74. As illustrated in FIGS. 5 and 6, first and second arcuate support elements 72, 74 each may be formed with partially cylindrical surfaces 68, 69, that are cylindrical about axes extending parallel to the length direction A of mast 30.

First support linkage 52 may include first arm 75 and second arm 76 spaced from each other along length direction A of mast 30 with first arm 75 being parallel to second arm 76. Similarly, second support linkage 56 may include first arm 77 and second arm 78 spaced from each other along length direction A of mast 30 with first arm 77 being parallel to second arm 78. A first mast bracket 79 and a first support element bracket 80 may be associated with first support linkage 52 and its first and second arms 75, 76. Similarly, a second mast bracket 81 and a second support element bracket 82 may be associated with second support linkage 56 and its first and second arms 77, 78. First mast bracket 79 may be fixed to first side element 44 on concave side 38 of mast 30. In like manner, second mast bracket 81 may be fixed to second side element 46. First support element bracket 80 may be fixed to first arcuate support element 72, and second support element bracket 82 may be fixed to second arcuate support element 74. First and second arms 75, 76 of first support linkage 52 may be pivotally connected to first mast bracket 79 via pivotal connections 83, 84 at first end 53 of first support linkage 52, and may be pivotally attached to first support element bracket 80 via pivotal connections 87, 88 at second end 54 of first support linkage 52. First and second arms 77, 78 of second support linkage 56 may be pivotally connected to second mast bracket 81 via pivotal connections 85, 86 at first end 57 of second support linkage 56, and may be pivotally attached to second support element bracket 82 via pivotal connections 89, 90 at second end 55 of second support linkage 56.

One of first and second arms 75, 76, for example second arm 76, of first support linkage 52, and one of first and second arms 77, 78, for example second arm 78, of second support linkage 56, may include an aperture 97, 98 for connection of a suitable actuator, for example a hydraulic cylinder. First and second actuators 40, 41, not shown in FIGS. 5 and 6 but visible in FIGS. 3 and 4, may be connected between one of first and second side elements 44, 46 and one of apertures 97, 98 in one of second arms 76, 78 for pivoting first and second support linkages 52, 56.

As will be apparent from the foregoing description and FIGS. 5 and 6, for example, first and second arms 75, 76 of first support linkage 52 along with first mast bracket 79 and first support element bracket 80 form a parallelogram linkage assembly. Accordingly, upon movement of first and second arms 75, 76 of first support linkage 52 via first actuator 40 in length direction A of mast 30 about pivotal connections 83, 84, the parallelogram arrangement will ensure that first arcuate support element 72 will maintain an orientation with the axis of partially cylindrical surface 68 of first arcuate support element 72 parallel to length direction A of mast 30. In like manner, upon movement of first and second arms 77, 78 of second support linkage 56 via second actuator 41 in length direction A of mast 30 about pivotal connections 85, 86, the parallelogram arrangement will ensure that second arcuate support element 74 will maintain an orientation with the axis of partially cylindrical surface 69 of second arcuate support element 74 parallel to length direction A of mast 30.

As more clearly illustrated in FIG. 6, first arm 75 of first support linkage 52 may be pivotally attached to first mast bracket 79 at two laterally spaced and coincident pivotal connections. Accordingly, first arm 75 may be attached to first mast bracket 79 at pivotal connection 83 as previously described, and also to adjacent pivotal connection 93 via branch element 94 fixed to first arm 75. In this embodiment, pivotal connection 84 for second arm 76 thus is a third pivotal connection for first support linkage 52 that is between the two laterally spaced and coincident pivotal connections 83, 93 and spaced from the two laterally spaced and coincident pivotal connections 83, 93 in length direction A of mast 30. Similarly, first arm 77 of second support linkage 56 may be pivotally attached to second mast bracket 81 at two laterally spaced and coincident pivotal connections. Accordingly, first arm 77 may be attached to second mast bracket 81 at pivotal connection 85 as previously described, and also to adjacent pivotal connection 95 via branch element 96 fixed to first arm 77. Pivotal connection 86 for second arm 78 thus is a third pivotal connection for second support linkage 56 that is between the two laterally spaced and coincident pivotal connections 85, 95 and spaced from the two laterally spaced and coincident pivotal connections 85, 95 in length direction A of mast 30.

FIGS. 7-9 are perspective views of mast 30 and associated features including pipe rack carousel 62 described in connection with FIGS. 3 and 4, and including deck wrench 58 employed to hold a drill pipe section 66 against rotation during addition or removal of another drill pipe section 66, and to support a drill pipe section that is disengaged from the gearbox (not shown) or drill column 65. In FIG. 7, first and second support linkages 52, 56 are illustrated in a position in which first and second arcuate support elements 72, 74 (only second arcuate support element 74 being visible in FIG. 7) engage and support a drill pipe section 66 as it is being transferred to drill column 65 or removed from drill column 65 and loaded onto pipe rack carousel 62.

FIG. 8 shows pipe rack carousel 62 pivoted away from drill column 65 and illustrates first and second support linkages 52, 56 in a position in which first and second arcuate support elements 72, 74 engage and support a drill pipe section 66 with an attached drill bit 50. FIG. 9 illustrates first and second support linkages 52, 56 in a disengaged position pivoted away from drill column 65 with first and second arcuate support elements 72, 74 adjacent side elements 44, 46 of mast 30. It is readily apparent from viewing FIG. 9 together with FIG. 8, for example, that first and second arcuate support elements 72, 74 remain in positions parallel to the length direction A of mast 30 at both the engagement position with a drill pipe section 66 illustrated in FIG. 8, and in the fully disengaged position illustrated in FIG. 9.

INDUSTRIAL APPLICABILITY

The disclosed pipe management system for negative angle drilling facilitates handling of drilling pipe in a platform based drill where a mast is capable of being pivoted to a negative angle for negative angle drilling. The disclosed open cross-section mast having the concave open side facing in the same direction that the mast leans during negative angle drilling is made more feasible and cost effective by being provided with the disclosed drill pipe handling system. While gravity tends to work with drill pipe when drilling vertically, gravity works against drill pipe during negative angle drilling by pulling it toward the open or concave side of the mast, particularly during loading drill pipe sections into the drill column and removing drill pipe sections from the drill column.

Advantageously, the disclosed pipe management system for negative angle drilling operates to fully support drill pipe and maintain it in alignment with the drill hole associated with the mast. In addition, the disclosed pipe management system for negative angle drilling facilitates loading and unloading drill pipe sections between the drill column and the carousel. The pipe handling unit is housed entirely within the mast itself and occupies a minimum of space thereby avoiding interference with other components associated with the mast. Also, the movement of the pipe handling unit along the length direction of the mast via a parallelogram linkage assembly involves a minimum of movement from a position engaging a drill pipe section to a disengaged position, and therefore requires less space for movement.

An exemplary method according to the disclosure of managing drill pipe to support negative angle drilling with a drilling machine including a mast having a length direction and a generally C-shaped cross section with a back element and first and second side elements partially enclosing a space and including an open front, is diagrammatically illustrated via flowchart 100 in FIG. 10. Referring to FIG. 10, the exemplary method may include, at box 102, pivoting the mast to a negative angle with the mast leaning from a vertical direction toward the direction of the open front and away from the back element.

At box 104, a pair of opposed arcuate support elements that are partially cylindrical about axes extending parallel to the length direction of the mast are moved in the length direction of the mast. At box 106, while moving the pair of opposed arcuate support elements, the axes are maintained extending parallel to the length direction of the mast to engage and support a section of drill pipe. At box 108, the pair of opposed arcuate support elements again are moved in the length direction of the mast. At box 110, while moving the pair of opposed arcuate support elements again, the axes are maintained extending parallel to the length direction of the mast to release the section of drill pipe.

For each moving of the pair of opposed arcuate support elements in the length direction of the mast, at box 112, parallel arms for each of the pair of opposed arcuate support elements may be moved, the parallel arms being attached to one of the first and second side elements of the mast at a first end of the arms and connected to the arcuate support elements at a second end of the arms. The mast may include a baseplate with a drill hole, and, at box 114, the section of drill pipe may be supported and maintained in alignment with the drill hole with the pair of opposed arcuate support elements. At box 116, each moving of the pair of opposed arcuate support elements in the length direction of the mast to support and release the section of drill pipe may be coordinated with loading and unloading the section of drill pipe from a pipe rack carousel and with operation of a deck wrench.

Use of the terms “substantially” and “generally” within this specification, (e.g., substantially parallel, generally C-shaped, etc.) is intended to take into account those situations wherein the components and relationships referenced may deviate from an absolute by normal and accepted convention, industry manufacturing tolerances, or industry field tolerances.

It will be apparent to those skilled in the art that various modifications and variations can be made in the disclosed pipe management system for negative angle drilling without departing from the scope of the disclosure. Other embodiments of the disclosed pipe management system for negative angle drilling will be apparent to those skilled in the art from consideration of the specification. It is intended that the specification and examples be considered as exemplary only, with a true scope of the disclosure being indicated by the following claims and their equivalents. 

What is claimed is:
 1. A pipe handling system for a platform based drill, comprising: a drilling platform including a frame structure having a first end, a second end opposite the first end, and first and second opposite sides; a mast supported on a pivotal connection to the drilling platform permitting the mast to be pivotally adjusted to a negative drilling angle whereby an upper portion of the mast leans in a first direction extending toward the first end of the frame structure and away from the second end of the frame structure, the mast including a length direction and having an open cross-section with a concave side facing in the first direction, and a convex side facing in a second direction opposite to the first direction; and a pipe handling unit mounted to the concave side of the mast and configured to support a drill pipe within the mast when the mast is pivotally adjusted to the negative drilling angle.
 2. The pipe handling system of claim 1, wherein the mast includes a back element and first and second side elements diverging from the back element.
 3. The pipe handling system of claim 2, wherein the pipe handling unit includes a first support linkage having first and second ends and pivotally attached at the first end to the first side element, and a second support linkage having first and second ends and pivotally attached at the first end to the second side element.
 4. The pipe handling system of claim 3, wherein the pipe handling unit includes a first arcuate support element pivotally connected to the second end of the first support linkage and a second arcuate support element pivotally connected to the second end of the second support linkage.
 5. The pipe handling system of claim 4, wherein the first and second support linkages are each pivotally attached to the first and second side elements via a mast bracket fixed to a respective side element, and wherein each of the first and second support linkages includes first and second parallel arms pivotally attached to a respective mast bracket.
 6. The pipe handling system of claim 5, wherein the first and second support linkages are each pivotally attached to the first and second arcuate guide elements via a guide element bracket fixed to a respective arcuate guide element, and wherein each of the first and second parallel arms is pivotally attached to a respective guide element bracket.
 7. The pipe handling system of claim 5, wherein the first parallel arm of each of the first and second support linkages is pivotally attached to the mast bracket at two laterally spaced and coincident pivotal connections, and the second parallel arm of each of the first and second support linkages is pivotally attached to the mast bracket at a third pivotal connection that is between the two laterally spaced and coincident pivotal connections and spaced from the two laterally spaced and coincident pivotal connections in the length direction of the mast.
 8. The pipe handling system of claim 7, further including a first actuator connected to the second parallel arm of the first support linkage for pivoting the first support linkage and a second actuator connect to the second parallel arm of the second support linkage for pivoting the second support linkage.
 9. The pipe handling system of claim 7, wherein the mast further includes a baseplate below the drilling platform, a drill hole located within the baseplate, a pipe rack carousel pivotally mounted adjacent the mast, and a deck wrench associated with the baseplate.
 10. A pipe handling unit on a mast of a drilling platform, comprising: a mast having a length direction and a generally C-shaped cross-section including a back element and first and second side elements partially enclosing a space within the mast, and including an open front; and a pipe handling unit within the space and including a first support linkage having first and second ends and pivotally attached at the first end to the first side element, and a second support linkage having first and second ends and pivotally attached at the first end to the second side element.
 11. The pipe handling unit of claim 10, wherein the first support linkage includes first and second arms spaced from each other along the length direction of the mast with the first arm of the first support linkage being parallel to the second arm of the first support linkage, and wherein the second support linkage includes first and second arms spaced from each other along the length direction of the mast with the first arm of the second support linkage being parallel to the second arm of the second support linkage.
 12. The pipe handling unit of claim 11, wherein the first and second arms of the first support linkage are pivotally connected to a first arcuate support element, and the first and second arms of the second support linkage are pivotally connected to a second arcuate support element.
 13. The pipe handling unit of claim 12, including an aperture in one of the first and second arms of each support linkage, and including an actuator connected between one of the first and second side elements and the aperture in one of the first and second arms of each support linkage for pivoting the first and second support linkages.
 14. The pipe handling unit of claim 13, wherein the first and second arcuate support elements are partially cylindrical about axes extending parallel to the length direction of the mast, and wherein during pivoting of the first and second support linkages the arcuate support elements maintain a position with the axes extending parallel to the length direction of the mast.
 15. The pipe handling unit of 12, including first and second mast brackets fixed to each of the first and second side elements, and first and second support element brackets fixed to each of the first and second arcuate support elements, and wherein the first support linkage is pivotally attached to the first side element via the first mast bracket, and the second support linkage is pivotally attached to the second side element via the second mast bracket.
 16. The pipe handling unit of claim 10, wherein the first and second side elements diverge from the back element with the open front having a greater width than the back element, and the first and second support linkages are pivotable to positions wherein they converge toward each other, further including an arcuate support element pivotally connected to each of the first and second support linkages with the arcuate support elements configured to substantially encircle a drill pipe when the first and second support linkages are pivoted to the positions wherein they converge toward each other.
 17. A method of managing drill pipe to support negative angle drilling with a drilling machine including a mast having a length direction and a generally C-shaped cross section with a back element and first and second side elements partially enclosing a space, and including an open front, the method comprising: pivoting the mast to a negative angle with the mast leaning from a vertical direction toward the direction of the open front and away from the back element; moving in the length direction of the mast a pair of opposed arcuate support elements that are partially cylindrical about axes extending parallel to the length direction of the mast; while moving the pair of opposed arcuate support elements, maintaining the axes extending parallel to the length direction of the mast to engage and support a section of drill pipe; moving the pair of opposed arcuate support elements again in the length direction of the mast; and while moving the pair of opposed arcuate support elements again, maintaining the opposed arcuate support elements parallel to the length direction of the mast to release the section of drill pipe.
 18. The method of claim 17, wherein each moving of the pair of opposed arcuate support elements in the length direction of the mast includes moving parallel arms for each of the pair of opposed arcuate support elements wherein the parallel arms are attached to one of the first and second side elements at a first end of the arms and connected to the arcuate support elements at a second end of the arms.
 19. The method of claim 17, wherein the mast further includes a baseplate with a drill hole, and further including supporting the section of drill pipe and maintaining the section of drill pipe in alignment with the drill hole with the pair of opposed arcuate support elements.
 20. The method of claim 17, including coordinating each moving of the pair of opposed arcuate support elements in the length direction of the mast to support and release the section of drill pipe with loading and unloading the section of drill pipe from a pipe rack carousel and with operation of a deck wrench mechanism. 